C# program for automatic web file download ?

[jmd]

Hello.
I want to write a C# program that does completely automatically what, until
now, I do manually, witch is describe below :
1. I launch IE (6)
2. I browse to my desired download page, say
http://www.site.com/download
This download page contains some textboxes, checkboxes,
radiobuttons, a DOWNLOAD BUTTON and text
3. I check some checkboxes, select some radiobuttons, enter text in some
textboxes and click on the download button
4. I receive a File Download Dialog
I browse to select a path/filename for the file
I click on the save button
The file is then saved on my pc.

Now I want a C# program that does the following :
1. Browses, SILENTLY, to my desired download page
(http://www.site.com/download) and fills in a form
SILENTLY means :
. no visible browse page (I do not want to see the download page
as in IE)
. C# code must be able to check some checkboxes, select some
radiobuttons, enter text in some textboxes
. after filling in data, C# code must be able to click the
Download button
2. C# code must be able to trap (event) the returned data, always
SILENTLY, i.e.
must be able to trap the File Download Dialog, fills somewhere
(?) a path/filename and download the file

Hope this is comprehensible.
Any help, code/articles/HowTos.../, is welcome.
Thank you very well in advance.
Jean-Marie